We appreciate the interest of the Leicester team and their co-authors.1 ,2 Their contributions to thoracic surgical service provision are internationally recognised. We agree with them that when variation in clinical practice is discovered, it merits critical examination. The discovery of variation provides the impetus to resolve the uncertainty that often underlies it. When there is good evidence for the effectiveness of surgery in particular patient groups, we can take an evidence based stance on which patients are being disadvantaged by variation in practice, but in the absence of evidence we should not assume that more care is better care.3 …